A couple of questions about Hidden Cache:
1) Do you get the 2 resource bonus when you use King Under the Mountain to discard it? I assume so, but I could be convinced otherwise.
2) I did a blind Vilya attempt and happened to hit Hidden Cache. It's clearly not discarded, so I can't get the two resources. But, do I get to draw a card for free or do I still have to pay one resource? It's a "0 cost" card, but the action has a "cost". How does "play for no cost" come into play here?